Corona treaters utilize high voltage electrodes to treat the surface of articles such as foils or films by electric discharge. The use of extremely high voltages on the discharge electrode results in very high discharge tube temperatures.
In the past, the discharge tube was cooled by passing large volumes of air across the tube at high speeds such as shown in U.S. Pat. No. 4,446,110. Such cooling systems did not lend themselves to use with corona treaters that utilize an inert or controlled atmosphere. Also, such cooling systems had inherent problems in that they introduced airborne particles and dust into the system and typically generated excessive noise.
While British Patent No. 2,022,323 A has suggested that discharge electrodes can be cooled by the use of a liquid cooling fluid, the actual structure and method of performing this method of cooling is left to the imagination.